An Efficient and Provably Secure ECC-Based Conditional Privacy-Preserving Authentication for Vehicle-to-Vehicle Communication in VANETs

In vehicular ad-hoc networks (VANETs), safety messages are exchanged among vehicles and between vehicles and infrastructure to ensure passengers' safety and efficiency in traffic. The source authentication as well as integrity checking of these messages are very necessary for a receiver. Based on certificateless cryptography (CLC), some state-of-the-art signature schemes have been proposed to address these. Although they fulfill the requirements of authentication and privacy, they are not efficient with respect to performance. Bilinear pairings and map-to-point hash functions are used in these schemes. These require a huge amount of time to process. The computational power and storing capacity of an on-board unit (OBU) in each vehicle are limited. Therefore, computational overhead is induced on vehicles that need to authenticate messages in areas of high traffic density. In this paper, a provably secure and efficient certificateless short signature-based conditional privacy-preserving authentication (CLSS-CPPA) scheme for V2V communication is designed. This scheme does not use bilinear parings and is based on the elliptic curve cryptosystem (ECC). In addition, instead of map-to-point hash functions, general hash functions are used. Furthermore, the CLSS-CPPA scheme supports the batch signature verification method which allows multiple signatures to be verified simultaneously and efficiently. The CLSS-CPPA scheme ensures security against type-I and type-II attackers with respect to existential unforgeability against adaptively chosen message attacks (EUF-CMA) under a hardness assumption of the elliptic curve discrete logarithm problem (ECDLP) in the random oracle model (ROM). The proposed scheme significantly improves performance in terms of computational and communication costs in comparison with state-of-the-art schemes.